The New South Wales State Emergency Service (SES) says it has received about 1,000 calls for help since a severe hail storm hit Sydney and the Blue Mountains late yesterday, adding to the backlog created by a powerful east coast low earlier in the week.

Hail and rain fell in torrents in parts of the Blue Mountains and Sydney, blanketing suburbs in ice and causing flash flooding in several places.

Cars were seen stranded on roadways as the water level rose, with five warehouses in Sydney’s west collapsing during the deluge.

One man had to be rescued after driving into floodwaters in Marrickville.

The SES says the storm resulted in about 1,000 calls for help on top of the almost 18,000 calls received across the state from the fatal storm at the beginning of the week.

“So if people have been able to use their own resources to address the issue, it would be appreciated if they could give us a call and we’ll take their name off the list.”

Senior BoM forecaster Jake Phillips told 702 ABC Sydney it was too early to say whether another east coast low was going to develop at the end of this week.

“There is some potential for a low to develop, but it is early days so our computer models are still undecided on that,” he said.

“I think it’s a bit too early to call at this stage.”

Workload through the roof: SES chief

SES Deputy Commissioner Steve Pearce told 702 ABC Sydney that the workload went “back through the roof” after the hail storm.

But he said there were over 1,000 people working through the jobs and other states were providing assistance.

“Today we should break the record books for the greatest amount of calls in New South Wales ever for a storm response, and that just shows the enormity of what has occurred,” he said.

“It’s basically a full campaign event now. One of the advantages in New South Wales is we have fantastic emergency management arrangements.

“When you have an event of this magnitude it surpasses the capability of one particular agency, so it’s an integrated approach now… we have all other emergency services in NSW in the game with us.”

The Bureau of Meteorology (BoM) said the amount of hail that fell was very unusual.